ALMA Update

1  Recent news

The major news in the international ALMA project was the signing of the North American contract for their share of the 12 m antennas for ALMA. The contract with Vertex Communications Corporation was signed on July 11, 2005 by Associate Universities, Incorporated (AUI), which operates NRAO for the NSF. The contract is to purchase at least 25 and up to 32 antennas. Anyone wanting to know more about it can check out the press release in the recent ALMA news section at www.alma.nrao.edu/almanews/ . It was originally hoped that ESO would be able to sign the contract for their half of the antennas on the same schedule. However, a decision on the ESO antenna contract has been delayed until the complete cost of ALMA has been re-estimated. We now hope that the contract for the European half of the antennas for ALMA can be signed in late October.
The major focus of activity in the international ALMA project over the summer continued to be the rebaselining of the project to bring it up to date since the definition of its schedule and budget in October 2002. This activity is now largely completed and a list of possible changes to the baseline ALMA project has been sent to the ALMA Board. Those changes which would have an impact on ALMA's scientific capabilities have also been sent to the ASAC for review (see next section). There will be a high-level international review of the cost of ALMA held in mid-October in Garching. The committee is chaired by Steve Beckwith and co-chaired by Thijs de Graauw.
In other ALMA news, the contracts for the foundation and shell of the technical building on the Array Operations Site in Chile were signed on August 2. This work marks the beginning of construction for ALMA on the high-site and is scheduled to be finished by March 2006. A new configuration design has been completed; this design is optimized for a 50 antenna ALMA, but can be expanded to give good performance with 64 antennas with a few additional pads. In science news, the new North American ALMA Science Center at NRAO is sponsoring a workshop in Charlottesville on (sub)millimeter spectroscopy of high-redshift galaxies. More information is available at http://www.cv.nrao.edu/naasc/zmachines/ and students are especially encouraged to attend.

2  ALMA Science Advisory Committee

The ASAC will be meeting October 1-2, 2005 in Santiago, Chile and so our major work over the summer has been preparing for that meeting. We have also been following the work on the rebaselining process and providing scientific input to the Board. The ASAC has four charges from the ALMA Board for this meeting: review the scientific impact of possible changes to the baseline ALMA coming from the rebaselining exercise; review the Scientific Specifications and Requirements document; continue our discussion from the previous two meetings on large projects, joint projects, and legacy projects; and discuss the scope and schedule of demonstration science with ALMA.
Since the information on the possible changes from the rebaselining process only became available this week, I will report on the results of the ASAC discussion of that charge in my next update. The ASAC set up two subcommittees to prepare discussion material on the last two charges in advance of the Santiago meeting. The need for an International TAC to deal with joint proposals and overlap between proposals submitted to the TACs of the different partners is again emerging from the discussion of the third charge. For demonstration science, we are considering explicitly separating the two functions (scientific commissioning using new projects; publicity images) that were linked together as demonstration science in the 2003-2004 ASAC reports. For anyone interested in more detail on the history of any of these charges, let me point out that all the ASAC reports, including the February 2005 meeting, are available on the NRAO ALMA web site at http://www.alma.nrao.edu/committees/ASAC/ .

3  ALMA Developments in Canada

3.1  Canadian ALMA Science Steering Committee

The Canadian ALMA Science Steering Committee (CASSC) met Sept 6-7, 2005 at the University of Calgary. The primary focus of the meeting was to discuss the charges given to the ASAC for their October 2005 meeting and also to consider how to position Canada to participate to maximum advantage in ALMA Operations. Since the committee was meeting in Calgary, we also heard reports from all of the Canadian software developers (Dave Fugate, Gary Li, and Raymond Rusk) and discussed issues and future directions for the Canadian ALMA software effort. We also heard a report on the Band 3 development effort, which is going extremely well (see next section).
Since the report from the meeting is not yet available, I want to highlight just a couple of key results here. While regretting the need to potentially reduce the number of antennas in ALMA from 64 to 50, the CASSC members voiced strong support for a 50 antenna ALMA and noted that it would still be a superb instrument capable of achieving the main science goals. For the operations era, the possibility of designing and operating the North American science archive for ALMA is a very attractive one which is both high profile and builds on existing archive expertise in Canada at the CADC.
Finally, it is clear that securing the remaining funding for the Long Range Plan is vital to completing our commitments to ALMA, since the funds remaining from the initial 5-year allocation will run out in 2007.

3.2  Band 3 Receiver Development

Tests on Band 3 cartridge #1 (see picture) are now nearly complete. NRAO has decided to re-schedule delivery of cartridge #1 to December 2005 in order to fit into their work plans at the Front End Integration Centre in Charlottesville. A few additional cartridge tests are proposed in the new cartridge test plan NRAO has proposed, and this re-scheduling will give us more time to to complete those tests. It will also give us time to complete shake and vibration tests before shipping the first cartridge to NRAO. A completely functional prototype cartridge has been built for this purpose, and we will use it to qualify the cartridge design and the shipping container we have developed.

Cartridge #2 has been completely assembled and its mechanical alignment tested and found to be well within specifications. Full testing will begin soon. The 2SB mixer assemblies for cartridge #2 have been assembled using SIS devices from the latest wafer produced by the University of Virginia. Testing indicates the new mixers noise temperatures are even better than those of cartridge #1, between 28 and 35 K.
The Band 3 Critical Design Review is currently scheduled to take place in March 2006, although this is still be be confirmed. The low-noise cryogenic IF amplifiers developed at HIA continues to attract attention from other receiver groups and low-temperature physics instrumentation groups.
For more information on the ALMA Band 3 Receiver Project contact Keith Yeung (Project Manager - keith.yeung@nrc-cnrc.gc.ca), Stephane Claude (Project Engineer - stephane.claude@nrc-cnrc.gc.ca), or Doug Johnstone (Project Scientist - doug.johnstone@nrc-cnrc.gc.ca).

 
   

 

3.3  Software

Canada contributes some effort towards the design of the central ALMA archive in co-operation with the European archive team. This work is done by the CADC in Victoria. Canadian work on the archive is set to accelerate with a revised agreement with the ALMA Computing team assigning an important component of the archive system to CADC, and we expect to fulfill our commitment in this area by 2007.
Raymond Rusk recently assumed primary responsibility for the Images module in AIPS++. This is an exciting opportunity because all ALMA Offline image analysis functionality lies within this module. This is also an area of development and maintenance that will remain important during the ALMA Operations phase. Chris Wilson attended a face-to-face meeting of the pipeline heuristics team in Socorro in July where one of the major topics of discussion was the scope and preparation for the next user test. The next pipeline software test will take place in late fall and will focus on flagging and calibration of single field interferometric data.

3.4  Personnel

Charles Cunningham from HIA has moved from Front-End IPT leader to a role in which he is the liaison between the North American half of ALMA B and the Japanese groups at the NAOJ in Tokyo. The primary objective of this role is to ensure that the Japanese contribution to ALMA is integrated efficiently, thereby minimizing the cost and schedule impact. This work started by advising and assisting the Japanese Band 4 and Band 8 teams in preparation for their preliminary design reviews, which were passed with flying colours in June 2005. In addition to providing instrumentation for the bilateral project, ALMA J will be procuring large quantities of equipment from ALMA B. The next major liaison task will be to ensure that the specification, interface, and procurement documentation are defined in a timely manner.
Chris Wilson wilson@physics.mcmaster.ca
Canadian ALMA Project Scientist
(with input from Charles Cunningham, Lewis Knee, and Raymond Rusk)


File translated from TEX by TTH, version 3.40.
On 03 Oct 2005, 20:36.